LHCb Collaboration(Aaij, R. et al), Oyanguren, A., & Ruiz Valls, P. (2013). Measurement of the B-0 -> K*(0) e(+) e(-) branching fraction at low dilepton mass. J. High Energy Phys., 05(5), 159–18pp.
Abstract: The branching fraction of the rare decay B-0 -> K*(0) e(+) e(-) in the dilepton mass region from 30 to 1000 MeV/c(2) has been measured by the LHCb experiment, using pp collision data, corresponding to an integrated luminosity of 1.0 fb(-1), at a centre-of-mass energy of 7 TeV. The decay mode B-0 -> J/psi (e(+) e(-)) K*(0) is utilized as a normalization channel. The branching fraction B(B-0 -> K*(0) e(+) e(-)) is measured to be B(B-0 -> K*(0) e(+) e(-))(30-1000 MeV/c2) = (3.1(-0.8)(-0.3)(+0.9)(+0.2) +/- 0.2) x 10(-7) where the fi rst error is statistical, the second is systematic, and the third comes from the uncertainties on the B-0 -> J/K*(0) and J/psi -> e(+) e(-) branching fractions.
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LHCb Collaboration(Aaij, R. et al), Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2021). Observation of the decay Lambda b0 -> chi(c1)p pi(-). J. High Energy Phys., 05(5), 095–21pp.
Abstract: The Cabibbo-suppressed decay Lambda b0</mml:msubsup>-> chi (c1)p(-) is observed for the first time using data from proton-proton collisions corresponding to an integrated luminosity of 6 fb(-1), collected with the LHCb detector at a centre-of-mass energy of 13 TeV. Evidence for the Lambda b0</mml:msubsup>-> chi (c2)p(-) decay is also found. Using the Lambda b0</mml:msubsup>-> chi (c1)pK(-) decay as normalisation channel, the ratios of branching fractions are measured to be<disp-formula id=“Equa”><mml:mtable displaystyle=“true”><mml:mtr><mml:mtd><mml:mfrac>B<mml:mfenced close=“)” open=“(”>Lambda b0</mml:msubsup>-> chi c1p pi-</mml:mfenced>B<mml:mfenced close=“)” open=“(”>Lambda b0</mml:msubsup>-> <mml:msub>chi c1pK-</mml:mfenced></mml:mfrac>=<mml:mfenced close=“)” open=“(”>6.59 +/- 1.01 +/- 0.22</mml:mfenced>x10-2,</mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mfrac>B<mml:mfenced close=“)” open=“(”>Lambda b0 -> <mml:msub>chi c2p pi-</mml:mfenced>B<mml:mfenced close=“)” open=“(”>Lambda b0 -> <mml:msub>chi c1p pi-</mml:mfenced></mml:mfrac>=0.95 +/- 0.30 +/- 0.04 +/- 0.04,</mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mfrac>B<mml:mfenced close=“)” open=“(”>Lambda b0 -> <mml:msub>chi c2pK-</mml:mfenced>B<mml:mfenced close=“)” open=“(”>Lambda b0 -> <mml:msub>chi c1pK-</mml:mfenced></mml:mfrac>=1.06 +/- 0.05 +/- 0.04 +/- 0.04,</mml:mtd></mml:mtr></mml:mtable><graphic position=“anchor” xmlns:xlink=“http://www.w3.org/1999/xlink” xlink:href=“13130 202115658 ArticleEqua.gif”></graphic></disp-formula><p id=“Par2”>where the first uncertainty is statistical, the second is systematic and the third is due to the uncertainties in the branching fractions of chi (c1,2)-> J/psi gamma decays.<fig id=“Figa” position=“anchor”><graphic position=“anchor” specific-use=“HTML” mime-subtype=“JPEG” xmlns:xlink=“http://www.w3.org/1999/xlink” xlink:href=“MediaObjects/13130 202115658 FigaHTML.jpg” id=“MO1”></graphic
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2018). Observation of the decay Lambda(0)(b) -> psi(2S)p pi(-). J. High Energy Phys., 08(8), 131–18pp.
Abstract: The Cabibbo-suppressed decay Lambda(0)(b) -> psi(2S)p pi(-) is observed for the fi rst time using a data sample collected by the LHCb experiment in proton-proton collisions corresponding to 1.0, 2.0 and 1.9 fb(-1) of integrated luminosity at centre-of-mass energies of 7, 8 and 13TeV, respectively. The psi(2S) mesons are reconstructed in the mu(+)mu(-) fi nal state. The branching fraction with respect to that of the Lambda(0)(b) -> psi(2S)pK(-) decay mode is measured to be B (Lambda(0)(b) -> psi(2S)p pi(-))/B (Lambda(0)(b) -> psi(2S)pK(-)) = (11.44 +/- 1.3 +/- 0.2)%, where the fi rst uncertainty is statistical and the second is systematic. The psi(2S) p and psi(2S)pi(-) mass spectra are investigated and no evidence for exotic resonances is found.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., et al. (2020). Observation of the semileptonic decay B+-> p(p)over-bar mu(+)nu(mu). J. High Energy Phys., 03(3), 146–22pp.
Abstract: The Cabibbo-suppressed semileptonic decay B+-> pp over bar mu+nu μis observed for the first time using a sample of pp collisions corresponding to an integrated luminosity of 1.0, 2.0 and 1.7 fb at centre-of-mass energies of 7, 8 and 13TeV, respectively. The differential branching fraction is measured as a function of the pp invariant mass using the decay mode B+ ! J= K+ for normalisation. The total branching fraction is measured to be B (B+ ! pp+) = (5:27+0:23 0:21 0:15) 10 where the first uncertainty is statistical, the second systematic and the third is from the uncertainty on the branching fraction of the normalisation channel.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2017). Updated branching fraction measurements of B-(s)(0) -> K(S)(0)h(+)h'(-) decays. J. High Energy Phys., 11(11), 027–42pp.
Abstract: The charmless three-body decays B-(s)(0) -> K(S)(0)h(+)h '(-) (where h((')) – pi, K) are analysed using a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 3 fb(-1). The branching fractions are measured relative to that of the B-0 -> K-S(0) pi(+)pi(-) decay, and are determined to be: B(B-0 -> (KSK +/-)-K-0 pi(-/+))/B(B-0 -> K-S(0)pi(+)pi(-) = 0.123 +/- 0.009 (stat) +/- 0.015 (syst), B(B-0 -> (KSK+K-)-K-0)/B(B-0 -> K-S(0)pi(+)pi(-) = 0.549 +/- 0.018 (stat) +/- 0.033 (syst), B(B-S(0) -> K-S(0) pi(+)pi(-))/B(B-0 -> K-S(0)pi(+)pi(-)) = 0.191 +/- 0.027 (stat) +/- 0.031 (syst) +/- 0.011 (f(s)/f(d)), B(B-0 -> (KSK +/-)-K-0 pi(-/+))/B(B-0 -> K-S(0)pi(+)pi(-) = 1.70 +/- 0.07 (stat) +/- 0.11 (syst) +/- 0.10 (f(s)/f(d)), B(B-0 -> (KSK+K-)-K-0)/B(B-0 -> K-S(0)pi(+)pi(-) is an element of [0.008 – 0.051] at 90% confidence level, where f(s)/f(d) represents the ratio of hadronisation fractions of the B-s(0) and B-0 mesons.
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LHCb Collaboration(Aaij, R. et al), Jaimes Elles, S. J., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Rebollo De Miguel, M., et al. (2023). Measurement of the CKM angle γ with B± → D[K∓π±π±π∓] h± decays using a binned phase-space approach. J. High Energy Phys., 07(7), 138–31pp.
Abstract: The CKM angle gamma is determined from CP-violating observables measured in B-+/- -> D[K--/+pi(+/-)pi(+/-)pi(-/+)]h(+/-), (h = K, pi) decays, where the measurements are performed in bins of the decay phase-space of the D meson. Using proton-proton collision data collected by the LHCb experiment at centre-of-mass energies of 7, 8 and 13TeV, corresponding to a total integrated luminosity of 9 fb(-1), gamma is determined to be gamma = (54.8 (+6.0)(-5.8) (+0.6)(-0.6) (+6.7)(-4.3))degrees, where the first uncertainty is statistical, the second systematic and the third from the external inputs on the coherence factors and strong phases of the D-meson decays.
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LHCb Collaboration(Aaij, R. et al), Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2021). Measurement of the CKM angle gamma and Bs0-Bs0bar mixing frequency with Bs0 -> Ds-/+ h +/ pi+/- pi-/+ decays. J. High Energy Phys., 03(3), 137–46pp.
Abstract: The CKM angle gamma is measured for the first time from mixing-induced CP violation between Bs0 -> Ds -/+ K pi +/- pi -/+ and Bs0bar -> Ds +/- K -/+ pi -/+ pi +/- decays reconstructed in proton-proton collision data corresponding to an integrated luminosity of 9 fb(-1) recorded with the LHCb detector. A time-dependent amplitude analysis is performed to extract the CP-violating weak phase gamma – 2 beta (s) and, subsequently, gamma by taking the Bs0-Bs0bar mixing phase beta (s) as an external input. The measurement yields gamma = (44 +/- 12) degrees modulo 180 degrees, where statistical and systematic uncertainties are combined. An alternative model-independent measurement, integrating over the five-dimensional phase space of the decay, yields gamma = (44 -13+20) degrees modulo 180 degrees. Moreover, the Bs0-Bs0bar oscillation frequency is measured from the flavour-specific control channel Bs0 -> Ds- pi+ pi+ pi- to be m(s) = (17.757 +/- 0.007(stat) +/- 0.008(syst)) ps(-1), consistent with and more precise than the current world-average value.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2018). Measurement of the CP asymmetry in B- -> (Ds-D0) and B- -> (D-D0) decays. J. High Energy Phys., 05(5), 160–17pp.
Abstract: The CP asymmetry in B- -> (Ds-D0) and B- -> (D-D0) decays is measured using LHCb data corresponding to an integrated luminosity of 3.0 fb(-1), collected in pp collisions at centre-of-mass energies of 7 and 8TeV. The results are A(CP) (B- -> (Ds-D0)) = (-0.4 +/- 0.5 +/- 0.5)% and A(CP) (B- -> (D-D0)) = (2.3 +/- 2.7 +/- 0.4)%, where the first uncertainties are statistical and the second systematic. This is the first measurement of A(CP) (B- -> (Ds-D0)) and the most precise determination of A(CP) (B- -> (D-D0)). Neither result shows evidence of CP violation.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., et al. (2020). Measurement of CP violation in B-0 -> (DD -/+)-D-*+/- decays. J. High Energy Phys., 03(3), 147–28pp.
Abstract: The decay-time-dependent CP asymmetry in B-0 -> (DD -/+)-D-*+/- decays is mea- sured using a data set corresponding to an integrated luminosity of 9 fb(-1) recorded by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The CP parameters are measured asSD*D=-0.861 +/- 0.077 +/- 0.019,Delta SD*D=0.019 +/- 0.075 +/- 0.012,CD*D=-0.059 +/- 0.092 +/- 0.020,Delta CD*D=-0.031 +/- 0.092 +/- 0.016,AD*D=0.008 +/- 0.014 +/- 0.006. The analysis provides the most precise single measurement of CP violation in this decay channel to date. All parameters are consistent with their current world average values.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., et al. (2020). Study of the psi(2)(3823) and chi(c1)(3872) states in B+->(J/psi pi(+)pi(-))K(+)decays. J. High Energy Phys., 08(8), 123–29pp.
Abstract: The decays B+-> J/psi pi(+)pi(-)K(+)are studied using a data set corresponding to an integrated luminosity of 9 fb(-1)collected with the LHCb detector in proton-proton collisions between 2011 and 2018. Precise measurements of the ratios of branching fractions with the intermediate psi(2)(3823), chi(c1)(3872) and psi(2S) states are reported. The values areBB+->psi 2(“>3823K+xB psi 2(”>3823 -> J/psi pi+pi-BB+->chi c1>3872K+xB chi c1>3872 -> J/psi pi+pi-=>3.56 +/- 0.67 +/- 0.11x10-2,BB+->psi 2>3823K+xB psi 2>3823 -> J/psi pi+pi-BB+->psi>2SK+xB psi>2S -> J/psi pi+pi-=>1.31 +/- 0.25 +/- 0.04x10-3,BB+->chi c1>3872K+xB chi c1>3872 -> J/psi pi+pi-BB+->psi>2SK+xB psi>2S -> J/psi pi+pi-= where the first uncertainty is statistical and the second is systematic. The decay of B+->psi(2)(3823)K(+)with psi(2)(3823)-> J/psi pi(+)pi(-)is observed for the first time with a significance of 5.1 standard deviations. The mass differences between the psi(2)(3823), chi(c1)(3872) and psi(2S) states are measured to be m chi c1>3872-m psi 2>3823=47. 50 +/- 0.53 +/- 0.13MeV/c2,m psi 2 2S=185.49 +/- 0.06 +/- 0.03MeV/c2, resulting in the most precise determination of the chi(c1)(3872) mass. The width of the psi(2)(3823) state is found to be below 5.2 MeV at 90% confidence level. The Breit-Wigner width of the chi(c1)(3872) state is measured to be Gamma chi c13872BW=0.96-0.18+0.19 +/- 0.21MeV={0.96}_{-0.18}<^>{+0.19}\pm 0.21\;\mathrm{MeV} which is inconsistent with zero by 5.5 standard deviations.
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